RESEARCHERS DISCOVER NEW WAYS TO PREDICT PATIENTS RISK FOR ADVANCED COLORECTAL CANCER

March is Colorectal Cancer Awareness Month

Chicago, IL -- Researchers have identified factors that may determine which patients are at more risk for developing certain types of colorectal cancer, according to two new studies published today in the February 2001 issue of Diseases of the Colon and Rectum, the official journal of the American Society of Colon and Rectal Surgeons. These findings may help physicians better screen for the disease and know which patients to aggressively treat to improve their chances of survival. The results come just prior to Colorectal Cancer Awareness Month in March.

Certain Factors Associated with Upper-Colon Cancer

The first study, conducted by researchers at University of South Florida in Tampa, demonstrated that increasing age; female gender; black, non-Hispanic race; and the presence of certain comorbid illnesses were factors associated with a greater likelihood of developing colorectal cancer in the upper colon. Patients with upper colon cancer tend to be diagnosed at a more advanced stage and have a lower survival rate compared to patients with the disease in the lower colon.

"This is the first time that an association has been made between specific comorbid illnesses (congestive heart failure, peptic ulcer, and diabetes mellitus) and colorectal cancer being located in the upper colon," explained study researcher Eduardo C. Gonzalez, MD, of the University of South Florida. "Knowing which individuals may be at more risk for upper colon cancer will aid physicians in determining the best screening test to use with them."

The observational study included 9,550 patients registered in Floridas population-based statewide cancer registry. Patients were categorized as having colorectal cancer in either the proximal (upper) or distal (lower) colon, and four characteristics emerged as independent predictors of an increase in the odds of a patient having proximal colorectal cancer:
- Each year of increasing age was associated with a 2.2 percent increase;
- Female gender was associated with a 38 percent increase;
- The presence of congestive heart failure, peptic ulcer, and diabetes mellitus was associated with a 28 percent increase;
- Black, non-Hispanic race was associated with a 24 percent increase.

"Colorectal cancer annually strikes about 140,000 people and causes 56,000 deaths," said American Society of Colon and Rectal Surgeons President and colorectal surgeon John MacKeigan, MD, of Michigan
State University. "However, it is a preventable and curable disease if detected and treated in its early stages. Screening is essential because colorectal cancer usually has no symptoms in its early stages."

"Everyone should be tested beginning at age 50, but those falling into an increased risk category, such as those identified in this study, should consult their colon and rectal surgeon or other health care provider to see if they need to be screened earlier," Dr. MacKeigan emphasized.

Predictor of Recurrent Colorectal Cancer in Patients with Early Colorectal Cancer

The second study was conducted in 261 patients at Singapore General Hospital in Singapore by researchers in the Department of Colorectal Surgery. In it, they discovered that elevated levels of an intracellular protein at the time of surgery for potentially curable colorectal cancer predicted an increased risk of recurrent cancer that has metastasized. Metastasized cancer is a more advanced form of the disease that has spread to other organs and generally has a lower survival rate.

The protein, carcinoembryonic antigen (CEA), can be measured with an inexpensive and simple test. CEA is normally found in low concentrations in embryonic and fetal gut, pancreatic, and liver cells, and levels of it may be elevated in smokers and in some malignant and benign conditions of the gastrointestinal tract.

"This study shows that patients thought to have early colorectal cancer without detectable spread to other organs but with elevated CEA levels may benefit from chemotherapy given in conjunction with surgery to improve their chance of long-term survival," concluded colorectal surgeon Francis Seow-Choen, MD, at Singapore General Hospital.

In the study, 85 of 261 patients developed recurrences of colorectal cancer. Of those patients, 5.3 percent had isolated local recurrence, 21 percent had isolated distant metastasis and 5.7 percent had both local recurrence and distant metastasis.

Patients with distant metastatic recurrence had a significantly higher CEA than those without recurrence: No patient with a CEA level of less than 1 ng/ml developed metastatic recurrence in this series. Twenty-three percent of all patients with a raised CEA above 5 ng/ml developed a metastatic lesion within two years, compared with 2.1 percent of patients with a CEA below 5 ng/ml.

The American Society of Colon and Rectal Surgeons (ASCRS) is the leading professional society of colorectal surgeons. ASCRS represents more than 1,000 board-certified colon and rectal surgeons and other surgeons dedicated to advancing and promoting the science and practice of the treatment of patients with diseases and disorders affecting the colon, rectum, and anus. Diseases of the Colon & Rectum features original papers that significantly advance knowledge within the field of colon and rectal surgery. Contents of the journal include case reports, technical notes and updates on recent advances in colorectal treatments. For more information, access the ASCRS Website at www.fascrs.org, or a directory of colorectal surgeons may be accessed at www.fascrs.org/directory.

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